Anterior Fontanelle Size in Healthy Indian Late Preterm and Full Term Newborns

Objective To measure the size of the anterior fontanelle (AF) in healthy late-preterm and term newborns and correlate it with birth weight, gestational age, gender, occipito-frontal circumference, small for gestational age status and birth weight z-score. Methods This was an observational study carried out from October 2013 through April 2015 at a tertiary care hospital. Newborns >= 34 wk gestation were enrolled. Fontanelle edge was palpated with index finger and size calculated by adding anterior-posterior and transverse diameters and dividing by two. Results A total of 1010 neonates were enrolled. The mean AF size was 2.23 +/- 0.52 cm (mean +/- SD). There was a significant decrease in the size of the AF with advancing gestational maturity on one-way ANOVA (F = 31.30) (P < 0.001) and also by increasing birth weight (F = 20.34) (P < 0.001). There was no significant difference in the mean AF size between males; 2.21 +/- 0.54 cm and females; 2.25 +/- 0.55 cm (mean +/- SD) (P = 0.575). There was a strong correlation between AF size with increasing birth weight; correlation (r) = 0.985. In small for gestational age neonates the AF was larger, 2.27 +/- 0.55 (mean +/- SD) and a strong correlation between birth weight z-score and AF size was noted (r = 1.012). Conclusions The mean AF size in late-preterm and term Indian newborns in a mixed community hospital was 2.23 +/- 0.52. A strong correlation was found between AF size with increasing birth weight and with birth weight z-score in small for gestational age babies.